A catheter guidance system and method for guiding a catheter through the bloodstream of the patients cardiovascular system in a medical procedure. The catheter has a front tip with a heating element for slightly heating a media surrounding the front tip in a blood vessel of the patients cardiovascular system, and two temperature measuring elements located adjacent to and in front and behind the heating element respectively for measuring temperatures in the media at their respective locations. A guidance device is coupled to the catheter for converting the heating power and temperature measurement signals to digital signals, processing the digital signals, and displaying guidance information indicative of the location of the front tip of the catheter relative to the blood vessel wall of the patients cardiovascular system. The guidance information may be shown by an intuitive traffic light type display.
